Rose's Note in Fable II is something that will arrive to the Hero of Bowerstone through Theresa after The Spire is destroyed and Lucien is killed. If, however, the Hero chooses to save his/her family through one of the choices, Rose comes back and the note may not be recieved.
Many people debate this topic. Many things are left unanswered at the end of Fable II which causes a lot of arguments. Some people debate Theresa also. People who have not played Fable: The Lost Chapters do not particularly know about Theresa, so they think Rose may be alive. Leave your say down below and remember, sign your posts with four tildes (~)!